1. Field of the Invention
The invention relates to a method for adjusting an optical rotating data transmission device having two units that are rotatable with respect to each other about a rotation axis, which each have a coaxial collimator for coupling light in or out, and also an optical rotating data transmission device that is adjustable by means of the method, and furthermore, an apparatus for performing the method.
2. Description of the Related Art
A single-channel, single-mode rotating data transmission device is disclosed in U.S. Pat. No. 5,039,193. GRIN lenses are used as collimators.
U.S. Pat. No. 4,815,812, discloses another single-channel rotating data transmission device in which the collimators in the form of GRIN lenses are accommodated in ferrules. The position of these ferrules is adjustable in one plane perpendicular to the rotation axis by means of adjusting screws, and may be fixed by means of an epoxy resin after adjustment.
With rotating data transmission devices of the species mentioned initially, the optical axes of the collimators must be coaxial to the rotation axis of the units. Each deviation of the axes from each other leads to an attenuation of the signal, i.e. to a deterioration of the transmission quality. The adjustment of a rotating data transmission device is frequently not possible for reasons of design, or attended by very high outlay. Therefore, prefabricated collimators having close tolerances must be employed. Particularly with GRIN lenses, there is a problem of the optical axis being tilted with respect to the geometrical axis. Here only expensive, pre-selected components can be employed.